1. Field of the Invention
The present invention generally relates vehicle emissions interfaces.
2. Description of Related Art
From 1996-present, vehicles have onboard diagnostics which allow technicians and emissions test stations to evaluate the vehicle's condition. The vehicle's electronic control unit (ECU) was designed from the factory to continuously test its own emissions and only set the emissions monitors to “ready” once those tests have successfully completed. If the tests are not completed, or if they have failed, the monitor status is reported as “not ready”.
When vehicles are brought in for state emissions, they are tested by a state-authorized facility that plugs a scantool into the vehicle's OBD-II port. When connected, the scantool checks the ECU to see if any trouble codes are present, and if all of the vehicle's emission monitors have passed. If all of the monitors have passed and no trouble codes are present, the vehicle passes the states emissions test. If any trouble codes are present or if any of the monitors have not completed their tests, the vehicle fails the state emissions test. In many states, this emissions test is required for annual or bi-annual registration.
In some emissions testing programs, the inspection tool performing the emissions testing must be regularly audited to verify proper operation. When an inspection tool is audited, normally a designated auditor visits the admissions test station and connects a vehicle simulator to the inspection tool. The vehicle simulator essentially acts like an OBD-II vehicle and allows the auditor to test several pass/fail scenarios on the inspection tool. If the inspection tool properly identifies each pass/fail scenario, the tool is certified. If the inspection tool does not properly identify each pass and fail scenario, the tool is no longer certified.
However, current vehicle simulators used for auditing have several limitations. For example, even though modern vehicles are increasingly complex with many ECU's on board, simulators currently used for testing only simulate one ECU. The simulators also have a limited number of pass/fail scenarios that must be preprogrammed prior to use and are difficult or impossible to modify in the field.